1) a bluish or purplish coloration of a guy's ballbag caused by the settling of blood in the veins in the scrotum, and...

2) sensitivity in the groin area that can range from very erotic to extreme pain.

Blue balls result from repeated stimulation of one's cock for a period of time without getting to orgasm / ejaculation.

Examples include repeatedly jerking off up to the point where one needs to cum; repeatedly receiving head or getting hand jobs from a partner but not cumming. Seriously kissing and fooling around with a (str8 or gay) partner over an extended period of time.

1) I stroked my dick for three hours while watching porn and got blue balls till I hurt so bad I just had to jack off.

2) After a couple hours of deep kissing, playing with her tits, her sucking my cock and me finger-fucking her ass, I had blue balls bad. She looked at me, chuckled and said, "Let me suck you off so you get some relief."

Blue balls happens when your with someone, kissing or something, and you are aroused for a long period of time, but you never ejaculate. Your balls may get bigger, or even shrink a little, and there is a slight bluish greyish color sometimes.
The pain is pretty bad. If you walk around, your balls and stomach hurts, but for a long time. It feels like you were kicked in the nuts, like when you get that stomach hurting feeling after being kicked there.
To cure: Have your partner finish you, or (God forbid), you gotta jack off. Without cumming, your balls can hurt for awhile. You gotta be careful not to go to fast because it hurts. IMPORTANT: This is kinda funny, but when you jack off after having blue balls, you will cum SO MUCH!! When I dont got blue balls, I cum like one solid piece, but with bllue balls I shot out like (No kidding), 5 good, solid shots. Be ready. Kinda like a cheap porno.

YOU: After Jenna came over, we kissed for awhile, but she left before we could do it.